Before you run your app, you should be aware of a few some important
directories and files in the Android project as follows:
Name
|
Description
|
1.
Manifest.xml
|
This is a main file, that describes the
fundamental characteristics of the application project
|
2.
Java
|
This contains the .java source
files for your project. By default, it includes an MainActivity.java source file
|
3.
drawable
|
This
contains all .png images that
included in your project
|
4.
layout
|
This is a directory for files that define your
app's user interface.
|
5.
values
|
This is a directory for other various XML files
that contain a collection of resources, such as strings and colors
definitions.
|
6.
build.gradle
|
This is an auto generated file which contains
compileSdkVersion, buildToolsVersion, applicationId, minSdkVersion,
targetSdkVersion, versionCode and versionName, etc.
|
Following are important brief overview of the
important above files:
The Manifest File
This
file resides at the root of the application project directory. This file works
as an interface between Android OS
and your application, then it will not be considered by the OS. For example, a
default manifest file :-
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.exam.myworld.hello">
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
Main Activity File
This is
a Java file MainActivity.java. Following is the default generated source code
of application wizard for Hello World! application :-
package com.myworld.hello;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
}